The specific aims are: Aim 1. Does a dietary pattern either high or low in available carbohydrate and fat alter the pattern of change observed in circulating factors involved in glucose homeostasis, chronic inflammation, cellular oxidation, and steroid hormone metabolism during progressive loss of body fat? The investigators will also examine how observed changes in these circulating factors related to changes indicators of breast cancer recurrence. Aim 2. Do circulating factors associated with glucose homeostasis, chronic inflammation, and cellular oxidation display the same pattern of change in response to progressive fat loss as circulating analytes associated with sex steroid metabolism? Analytes of interest will be measured monthly throughout the study. Aim 3. Does dietary glycemic load affect the magnitude or rate of fat loss? Plasma adipokines such as leptin and adiponectin and plasma ghrelin will be measured to provide biological determinants that may help explain differences in response.